package com.lagou.kafka.demo.consumer;

import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.clients.consumer.ConsumerRecords;
import org.apache.kafka.clients.consumer.KafkaConsumer;
import org.apache.kafka.common.serialization.IntegerDeserializer;
import org.apache.kafka.common.serialization.StringDeserializer;

import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.function.Consumer;

/**
 * @param
 * @author oyz
 * @version 1.0
 * @description:  消费者
 * @date 2022/3/25 17:01
 */
public class MyConsumer2 {

    public static void main(String[] args) {
        Map<String,Object> configs = new HashMap<>(5);
        configs.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG,"192.168.106.130:9092");
        configs.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, IntegerDeserializer.class);
        configs.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
        // 配置消费组ID
        configs.put(ConsumerConfig.GROUP_ID_CONFIG,"consumer_demo");
        // 如果找不到当前消费者的有效偏移量,则自动重置到最开始的位置
        // lastest表示直接充值到消息偏移量的最后一个位置
        configs.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG,"earliest");
        KafkaConsumer<Integer, String> consumer = new KafkaConsumer<>(configs);

        // 先订阅,再消费
        consumer.subscribe(Arrays.asList("topic_1"));
        while (true){

            // 批量的从主题分区中拉取消息
            ConsumerRecords<Integer, String> message = consumer.poll(3000);
            message.forEach(new Consumer<ConsumerRecord<Integer, String>>() {
                @Override
                public void accept(ConsumerRecord<Integer, String> record) {
                    System.out.println(record.topic()+"\t"+record.partition()+"\t"+record.key()+"\t"
                            + record.value() +"\t"+record.offset());
                }
            });
        }


    }
}
